Adds redis sentinel support

.drone.yml

@@ -46,6 +46,9 @@ steps:
     ATHENS_MONGO_STORAGE_URL: mongodb://mongo:27017
     ATHENS_MINIO_ENDPOINT: minio:9000
     REDIS_TEST_ENDPOINT: redis:6379
+    REDIS_SENTINEL_TEST_ENDPOINT: redis-sentinel:26379
+    REDIS_SENTINEL_TEST_MASTER_NAME: redis-1
+    REDIS_SENTINEL_TEST_PASSWORD: sekret
     PROTECTED_REDIS_TEST_ENDPOINT: protectedredis:6380
     ATHENS_PROTECTED_REDIS_PASSWORD: AthensPass1
     GCS_SERVICE_ACCOUNT:
@@ -156,13 +159,21 @@ services:
   image: redis
   ports:
     - 6379
+- name: redis-sentinel
+  image: bitnami/redis-sentinel
+  environment:
+    REDIS_MASTER_HOST: redis
+    REDIS_MASTER_SET: redis-1
+    REDIS_SENTINEL_PASSWORD: sekret
+    REDIS_SENTINEL_QUORUM: "1"
+  ports:
+    - 26379
 - name: protectedredis
   image: redis
   ports:
     - 6380
   commands:
     - "redis-server ./test/redis.conf"
-
 - name: athens-proxy
   image: gomods/athens:canary
   pull: always

cmd/proxy/actions/app_proxy.go

@@ -133,6 +133,16 @@ func getSingleFlight(c *config.Config, checker storage.Checker) (stash.Wrapper,
 			return nil, fmt.Errorf("Redis config must be present")
 		}
 		return stash.WithRedisLock(c.SingleFlight.Redis.Endpoint, c.SingleFlight.Redis.Password, checker)
+	case "redis-sentinel":
+		if c.SingleFlight == nil || c.SingleFlight.RedisSentinel == nil {
+			return nil, fmt.Errorf("Redis config must be present")
+		}
+		return stash.WithRedisSentinelLock(
+			c.SingleFlight.RedisSentinel.Endpoints,
+			c.SingleFlight.RedisSentinel.MasterName,
+			c.SingleFlight.RedisSentinel.SentinelPassword,
+			checker,
+		)
 	case "gcp":
 		if c.StorageType != "gcp" {
 			return nil, fmt.Errorf("gcp SingleFlight only works with a gcp storage type and not: %v", c.StorageType)

config.dev.toml

@@ -263,7 +263,7 @@ DownloadURL = ""
 # and the second request will wait for the first one to finish so that
 # it doesn't override the storage.
 
-# Options are ["memory", "etcd", "redis", "gcp", "azureblob"]
+# Options are ["memory", "etcd", "redis", "redis-sentinel", "gcp", "azureblob"]
 
 # The default option is "memory" which means that only one instance of Athens
 # should be used.
@@ -275,6 +275,10 @@ DownloadURL = ""
 # and therefore it will use its strong-consistency features to ensure
 # that only one module is ever written even when concurrent saves happen
 # at the same time.
+# The "redis" single flight will use a single redis instance as a locking mechanism
+# for updating the underlying storage
+# The "redis-sentinel" single flight works similarly to "redis" but obtains a redis connection
+# via a redis-sentinel
 # Env override: ATHENS_SINGLE_FLIGHT_TYPE
 SingleFlightType = "memory"
 
@@ -290,6 +294,17 @@ SingleFlightType = "memory"
         # TODO(marwan): enable multiple endpoints for redis clusters.
         # Env override: ATHENS_REDIS_ENDPOINT
         Endpoint = "127.0.0.1:6379"
+    [SingleFlight.RedisSentinel]
+        # Endpoints is the redis sentinel endpoints to discover a redis 
+        # master for a SingleFlight lock.
+        # Env override: ATHENS_REDIS_SENTINEL_ENDPOINTS
+        Endpoints = ["127.0.0.1:26379"]
+        # MasterName is the redis sentinel master name to use to discover
+        # the master for a SingleFlight lock
+        MasterName = "redis-1"
+        # SentinelPassword is an optional password for authenticating with
+        # redis sentinel
+        SentinelPassword = "sekret"
 
         # Password is the password for a redis SingleFlight lock.
         # Env override: ATHENS_REDIS_PASSWORD

docker-compose.yml

@@ -81,6 +81,15 @@ services:
     image: redis
     ports:
       - 6379:6379
+  redis-sentinel:
+    image: bitnami/redis-sentinel
+    environment:
+      - REDIS_MASTER_HOST=redis
+      - REDIS_MASTER_SET=redis-1
+      - REDIS_SENTINEL_PASSWORD=sekret
+      - REDIS_SENTINEL_QUORUM=1
+    ports:
+      - 26379:26379
   protectedredis:
     image: redis
     ports:

docs/content/configuration/storage.md

@@ -335,3 +335,95 @@ It assumes that you already have the following:
             # Name of container in the blob storage
             # Env override: ATHENS_AZURE_CONTAINER_NAME
             ContainerName = "MY_AZURE_BLOB_CONTAINER_NAME"
+
+## Running multiple Athens pointed at the same storage
+
+Athens has the ability to run concurrently pointed at the same storage medium, using
+a distributed locking mechanism called "single flight".
+
+By default, Athens is configured to use the `memory` single flight, which
+stores locks in local memory. This works when running a single Athens instance, given
+the process has access to it's own memory. However, when running multiple Athens instances
+pointed at the same storage, a distributed locking mechansism is required.
+
+Athens supports several distributed locking mechanisms:
+
+- `etcd`
+- `redis`
+- `redis-sentinel`
+- `gcp` (available when using the `gcp` storage type)
+- `azureblob` (available when using the `azureblob` storage type)
+
+Setting the `SingleFlightType` (or `ATHENS_SINGLE_FLIGHT TYPE` in the environment) configuration
+value will enable usage of one of the above mechanisms. The `azureblob` and `gcp` types require
+no extra configuration.
+
+### Using etcd as the single flight mechanism
+
+Using the `etcd` mechanism is very simple, just a comma separated list of etcd endpoints.
+The recommend configuration is 3 endpoints, however, more can be used.
+
+    SingleFlightType = "etcd"
+
+    [SingleFlight]
+        [SingleFlight.Etcd]
+            # Env override: ATHENS_ETCD_ENDPOINTS
+            Endpoints = "localhost:2379,localhost:22379,localhost:32379"
+
+### Using redis as the single flight mechanism
+
+Athens supports two mechanisms of communicating with redis: direct connection, and
+connecting via redis sentinels.
+
+#### Direct connection to redis
+
+Using a direct connection to redis is simple, and only requires a single `redis-server`.
+You can also optionally specify a password to connect to the redis server with
+
+    SingleFlightType = "redis"
+
+    [SingleFlight]
+        [SingleFlight.Redis]
+            # Endpoint is the redis endpoint for the single flight mechanism
+            # Env override: ATHENS_REDIS_ENDPOINT
+            Endpoint = "127.0.0.1:6379"
+
+            # Password is the password for the redis instance
+            # Env override: ATHENS_REDIS_PASSWORD
+            Password = ""
+
+#### Connecting to redis via redis sentinel
+
+**NOTE**: redis-sentinel requires a working knowledge of redis and is not recommended for
+everyone.
+
+redis sentinel is a high-availability set up for redis, it provides automated monitoring, replication,
+failover and configuration of multiple redis servers in a leader-follower setup. It is more
+complex than running a single redis server and requires multiple disperate instances of redis
+running distributed across nodes.
+
+For more details on redis-sentinel, check out the [documentation](https://redis.io/topics/sentinel)
+
+As redis-sentinel is a more complex set up of redis, it requires more configuration than standard redis.
+
+Required configuration:
+
+- `Endpoints` is a list of redis-sentinel endpoints to connect to, typically 3, but more can be used
+- `MasterName` is the named master instance, as configured in the `redis-sentinel` [configuration](https://redis.io/topics/sentinel#configuring-sentinel)
+
+Optionally, like `redis`, you can also specify a password to connect to the `redis-sentinel` endpoints with
+
+    SingleFlightType = "redis-sentinel"
+
+    [SingleFlight]
+      [SingleFlight.RedisSentinel]
+          # Endpoints is the redis sentinel endpoints to discover a redis
+          # master for a SingleFlight lock.
+          # Env override: ATHENS_REDIS_SENTINEL_ENDPOINTS
+          Endpoints = ["127.0.0.1:26379"]
+          # MasterName is the redis sentinel master name to use to discover
+          # the master for a SingleFlight lock
+          MasterName = "redis-1"
+          # SentinelPassword is an optional password for authenticating with
+          # redis sentinel
+          SentinelPassword = "sekret"

go.mod

@@ -14,11 +14,13 @@ require (
 	github.com/DataDog/opencensus-go-exporter-datadog v0.0.0-20180917103902-e6c7f767dc57
 	github.com/aws/aws-sdk-go v1.15.24
 	github.com/bsm/redis-lock v8.0.0+incompatible
+	github.com/bsm/redislock v0.4.2
 	github.com/codegangsta/negroni v1.0.0 // indirect
 	github.com/fatih/color v1.7.0
 	github.com/go-playground/locales v0.12.1 // indirect
 	github.com/go-playground/universal-translator v0.16.0 // indirect
 	github.com/go-redis/redis v6.15.2+incompatible
+	github.com/go-redis/redis/v7 v7.2.0
 	github.com/gobuffalo/envy v1.6.7
 	github.com/gobuffalo/httptest v1.0.4
 	github.com/golang/snappy v0.0.1 // indirect

go.sum

@@ -54,6 +54,8 @@ github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kB
 github.com/bsm/go-vlq v0.0.0-20150828105119-ec6e8d4f5f4e/go.mod h1:N+BjUcTjSxc2mtRGSCPsat1kze3CUtvJN3/jTXlp29k=
 github.com/bsm/redis-lock v8.0.0+incompatible h1:QgB0J2pNG8hUfndTIvpPh38F5XsUTTvO7x8Sls++9Mk=
 github.com/bsm/redis-lock v8.0.0+incompatible/go.mod h1:8dGkQ5GimBCahwF2R67tqGCJbyDZSp0gzO7wq3pDrik=
+github.com/bsm/redislock v0.4.2 h1:+7WydoauDwf5Qw0ajaI/g3t26dQ/ovGU0Dv59sVvQzc=
+github.com/bsm/redislock v0.4.2/go.mod h1:zeuSDdDFtEDtbAgKsw7NDucfSVR0zLWBv8tMpro/6UM=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/codegangsta/negroni v1.0.0 h1:+aYywywx4bnKXWvoWtRfJ91vC59NbEhEY03sZjQhbVY=
 github.com/codegangsta/negroni v1.0.0/go.mod h1:v0y3T5G7Y1UlFfyxFn/QLRU4a2EuNau2iZY63YTKWo0=
@@ -90,6 +92,10 @@ github.com/go-playground/universal-translator v0.16.0 h1:X++omBR/4cE2MNg91AoC3rm
 github.com/go-playground/universal-translator v0.16.0/go.mod h1:1AnU7NaIRDWWzGEKwgtJRd2xk99HeFyHw3yid4rvQIY=
 github.com/go-redis/redis v6.15.2+incompatible h1:9SpNVG76gr6InJGxoZ6IuuxaCOQwDAhzyXg+Bs+0Sb4=
 github.com/go-redis/redis v6.15.2+incompatible/go.mod h1:NAIEuMOZ/fxfXJIrKDQDz8wamY7mA7PouImQ2Jvg6kA=
+github.com/go-redis/redis v6.15.7+incompatible h1:3skhDh95XQMpnqeqNftPkQD9jL9e5e36z/1SUm6dy1U=
+github.com/go-redis/redis/v7 v7.0.0-beta.4/go.mod h1:xhhSbUMTsleRPur+Vgx9sUHtyN33bdjxY+9/0n9Ig8s=
+github.com/go-redis/redis/v7 v7.2.0 h1:CrCexy/jYWZjW0AyVoHlcJUeZN19VWlbepTh1Vq6dJs=
+github.com/go-redis/redis/v7 v7.2.0/go.mod h1:JDNMw23GTyLNC4GZu9njt15ctBQVn7xjRfnwdHj/Dcg=
 github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/go-test/deep v1.0.1 h1:UQhStjbkDClarlmv0am7OXXO4/GaPdCGiUiMTvi28sg=
@@ -111,6 +117,8 @@ github.com/golang/protobuf v1.1.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
+github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/golang/snappy v0.0.1 h1:Qgr9rKW7uDUkrbSmQeiDsGa8SjGyCOGtuasMWwvp2P4=
 github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
@@ -209,9 +217,15 @@ github.com/olekukonko/tablewriter v0.0.0-20170122224234-a0225b3f23b5/go.mod h1:v
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0 h1:WSHQ+IS43OoUrWtD1/bbclrwK8TTH5hzp+umCiuxHgs=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/ginkgo v1.8.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/ginkgo v1.10.1 h1:q/mM8GF/n0shIN8SaAZ0V+jnLPzen6WIVZdiwrRlMlo=
+github.com/onsi/ginkgo v1.10.1/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/gomega v1.4.2/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/onsi/gomega v1.4.3 h1:RE1xgDvH7imwFD45h+u2SgIfERHlS2yNG4DObb5BSKU=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/onsi/gomega v1.5.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/onsi/gomega v1.7.0 h1:XPnZz8VVBHjVsy1vzJmRwIcSwiUO+JFfrv/xGiigmME=
+github.com/onsi/gomega v1.7.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/openzipkin/zipkin-go v0.1.6/go.mod h1:QgAqvLzwWbR/WpD4A3cGpPtJrZXNIiJc5AZX7/PBEpw=
 github.com/philhofer/fwd v1.0.0 h1:UbZqGr5Y38ApvM/V/jEljVxwocdweyH+vmYvRPBnbqQ=
 github.com/philhofer/fwd v1.0.0/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
@@ -333,6 +347,8 @@ golang.org/x/net v0.0.0-20190501004415-9ce7a6920f09/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20190502183928-7f726cade0ab/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092 h1:4QSRKanuywn15aTZvI/mIDEgPQpswuFndXpOj3rKEco=
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
+golang.org/x/net v0.0.0-20190923162816-aa69164e4478 h1:l5EDrHhldLYb3ZRHDUhXF7Om7MvYXnkV9/iQNo1lX6g=
+golang.org/x/net v0.0.0-20190923162816-aa69164e4478/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421 h1:Wo7BWFiOk0QRFMLYMqJGFMd9CgUAcGx7V+qEg/h5IBI=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -353,6 +369,8 @@ golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190502145724-3ef323f4f1fd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82 h1:vsphBvatvfbhlb4PO1BYSr9dzugGxJ/SQHoNufZJq1w=
 golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191010194322-b09406accb47 h1:/XfQ9z7ib8eEJX2hdgFTZJ/ntt0swNk5oYBziWeTCvY=
+golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
@@ -388,6 +406,7 @@ gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLks
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/cheggaaa/pb.v1 v1.0.25/go.mod h1:V/YB90LKu/1FcN3WVnfiiE5oMCibMjukxqG/qStrOgw=
 gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
@@ -403,6 +422,8 @@ gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWD
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 howett.net/plist v0.0.0-20181124034731-591f970eefbb/go.mod h1:vMygbs4qMhSZSc4lCUl2OEE+rDiIIJAIdR4m7MiMcm0=

pkg/config/config.go

@@ -164,6 +164,11 @@ func defaultConfig() *Config {
 		SingleFlight: &SingleFlight{
 			Etcd:  &Etcd{"localhost:2379,localhost:22379,localhost:32379"},
 			Redis: &Redis{"127.0.0.1:6379", ""},
+			RedisSentinel: &RedisSentinel{
+				Endpoints:        []string{"127.0.0.1:26379"},
+				MasterName:       "redis-1",
+				SentinelPassword: "sekret",
+			},
 		},
 	}
 }

pkg/config/singleflight.go

@@ -4,8 +4,9 @@ package config
 // backend configurations for a distributed
 // lock or single flight mechanism.
 type SingleFlight struct {
-	Etcd  *Etcd
-	Redis *Redis
+	Etcd          *Etcd
+	Redis         *Redis
+	RedisSentinel *RedisSentinel
 }
 
 // Etcd holds client side configuration
@@ -21,3 +22,11 @@ type Redis struct {
 	Endpoint string `envconfig:"ATHENS_REDIS_ENDPOINT"`
 	Password string `envconfig:"ATHENS_REDIS_PASSWORD"`
 }
+
+// RedisSentinel is the configuration for using redis with sentinel
+// for SingleFlight
+type RedisSentinel struct {
+	Endpoints        []string `envconfig:"ATHENS_REDIS_SENTINEL_ENDPOINTS"`
+	MasterName       string   `envconfig:"ATHENS_REDIS_SENTINEL_MASTER_NAME"`
+	SentinelPassword string   `envconfig:"ATHENS_REDIS_SENTINEL_PASSWORD"`
+}

pkg/stash/with_redis.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"time"
 
-	lock "github.com/bsm/redis-lock"
-	"github.com/go-redis/redis"
+	lock "github.com/bsm/redislock"
+	"github.com/go-redis/redis/v7"
 	"github.com/gomods/athens/pkg/config"
 	"github.com/gomods/athens/pkg/errors"
 	"github.com/gomods/athens/pkg/observ"
@@ -44,17 +44,15 @@ func (s *redisLock) Stash(ctx context.Context, mod, ver string) (newVer string,
 	mv := config.FmtModVer(mod, ver)
 
 	// Obtain a new lock with default settings
-	lock, err := lock.Obtain(s.client, mv, &lock.Options{
-		LockTimeout: time.Minute * 5,
-		RetryCount:  60 * 5,
-		RetryDelay:  time.Second,
+	lock, err := lock.Obtain(s.client, mv, time.Minute*5, &lock.Options{
+		RetryStrategy: lock.LimitRetry(lock.LinearBackoff(time.Second), 60*5),
 	})
 	if err != nil {
 		return ver, errors.E(op, err)
 	}
 	defer func() {
-		const op errors.Op = "redis.Unlock"
-		lockErr := lock.Unlock()
+		const op errors.Op = "redis.Release"
+		lockErr := lock.Release()
 		if err == nil && lockErr != nil {
 			err = errors.E(op, lockErr)
 		}

pkg/stash/with_redis_sentinel.go

@@ -0,0 +1,30 @@
+package stash
+
+import (
+	"github.com/go-redis/redis/v7"
+	"github.com/gomods/athens/pkg/errors"
+	"github.com/gomods/athens/pkg/storage"
+)
+
+// WithRedisSentinelLock returns a distributed singleflight
+// with a redis cluster that utilizes sentinel for quorum and failover
+func WithRedisSentinelLock(endpoints []string, master, password string, checker storage.Checker) (Wrapper, error) {
+	const op errors.Op = "stash.WithRedisSentinelLock"
+	// The redis client constructor does not return an error when no endpoints
+	// are provided, so we check for ourselves.
+	if len(endpoints) == 0 {
+		return nil, errors.E(op, "no endpoints specified")
+	}
+	client := redis.NewFailoverClient(&redis.FailoverOptions{
+		MasterName:       master,
+		SentinelAddrs:    endpoints,
+		SentinelPassword: password,
+	})
+	_, err := client.Ping().Result()
+	if err != nil {
+		return nil, errors.E(op, err)
+	}
+	return func(s Stasher) Stasher {
+		return &redisLock{client, s, checker}
+	}, nil
+}